Adsorptive removal of thallium(III) ions from aqueous solutions using eucalyptus leaves powders

Abstract

<span style="font-size:9.0pt;mso-bidi-font-size:11.0pt" lang="EN-GB">Adsorption of thallium(III) ions from aqueous solutions onto eucalyptus leaves powders as a low cost adsorbent has been studied in batch mode. It is observed that modification of the adsorbent with basic solution (NaOH solution) is essential for achieving a significant adsorption. The alkaline modified adsorbent shows a significant amount of adsorption. However, the adsorbent treated with nitric acid shows no activity. The effects of experimental conditions such as initial solution <i style="mso-bidi-font-style:normal">p</i>H, agitation speed, contact time, adsorbent amounts, initial thallium concentration and temperature are studied. The results show that adsorption is strongly <i style="mso-bidi-font-style:normal">p</i>H-dependent. The maximum adsorption of thallium(III) ion obtained at 25±1^oC is found to be 78.2%. The equilibrium data are described by the Langmuir isotherm but a slightly inferior fit is obtained using the Freundlich model. The monolayer saturation capacity is calculated to be 217.4 mg g^-1. The separation factor indicates that eucalyptus leaves powders are favorable for the sorption of thallium(III).

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